1. Field of the Invention
The present invention relates to computer networks in general and in particular to protecting said networks against malicious traffic.
2. Prior Art
Open access to public networks, such as the Internet, has made it easier for hackers to launch or disseminate harmful code known as worm, virus, etc. Because most private networks are coupled to the Internet viruses launched from public networks can affect not only devices connected to the public network but also devices connected to the private networks. With the advent of e-business and stock market activities, it is well known that large amounts of business transactions are consummated via computer networks. As a consequence a malicious person wishing to cause economic chaos could launch a virus from a public site to disrupt these transactions.
The prior art has recognized the need and has provided tools to be used on said computer networks to detect malicious viruses. For the most part these tools work well for their intended purpose. Stated another way the tools work well to detect the virus for which it was created to detect. If the characteristics of the virus change the tool may be worthless and not able to detect the new virus. It is well known that hackers are very intelligent individuals and are most likely to change virus characteristics to prevent detection.
In view of the above, prior art techniques which are primarily based upon comparison between a library of patterns in the tool and virus in a packet do not give a network administrator sufficient power and control to protect a computer network against malicious viruses. As a consequence a tool is required that does not protect computer network based upon virus pattern but on other characteristics or statistics of the packets sent maliciously. By so doing hackers may change the virus pattern at will. Yet still such malicious packets will still be detected.